Speed control device



April 2, 1940. G, DICKERSQN 2,195,562]

SPEED CONTROL DEVICE Filed Aprills. 1939 Y po/Mz 2%5 Patented -'Api'. 2,1940 UNI-TED STATI-:sx1PATENT] oFric-E ausser y c v nm, o. nimma,mamans. va..

Henry Wyatt Dickerson. Richm allgnorto omLVa.

inauguran anni 1s. ma. sei-la Nc. man

u cum (cl. 1oz-5s) The present invention relates to variable speed ashydraulic clutches or hydraulic drives. The

present invention differs from such devices in its general object, whichis the provision of a des vice which, although similar in certainrespects to the previously known hydraulic clutches and hydraulicdrives, is primarily intended as a variable speed drive, or device forcontrolling the speed of power driven machinery,"for example textilemachinery and the like, in which a more or less delicate speedregulation is desirable. In View of this consideration, it is an objectof the present invention to provide a device of the character described,which is capable of a very wide range of transmission ratios, and which,at the same time, is readily and easily adjustedover said range. l

Another object is the provision of a device of the character described,which is capable of transmitting more power, for its size, thanpreviously known hydraulic drives, due to the novel shape and relationof the driving and driven elements.

In the previously known devices of the general character in question, inwhich a pump has been employed, such as a gear pump or a vanetype pump,the pump has usually been associated with the driving element or thedriven element in such a manner that the power is transmitted directlythrough the pump elements, which accordingly resulted in a limitation onthe power capable of transmission, in accordance with the size andstrength of the pump employed. It is an object of the present inventionto avoid this disadvantage by causing the power to be transmitteddirectly from the driving to the driven element, through the fluidmedium, the pump being employed solely for the purpose of maintainingthe fluid medium speed constant. Another object is the provision, in akdevice of the character described, of manually- 'i may be varied as.desired.-`

-operated means for theafo'resaid. governor, so that the'speed of thedriven element A further' general object or the present invenv '-tionvis the provision of a device ofthe character described, which is ofsimple but rugged construcr tion and is economical to manufacture.

- Other and further objects, features and ad-l4 I vantages of thepresent invention will be apparent to one skilled in the art from thefollowing description taken in lconnection with the accom-r panyingdrawing in which: l

Figure l is a longitudinal vertical section through a variable speeddrive constructed in accordance with the present invention;

Figure 2 is a transverse section on line 2-2 of Figure 1;

Figure 3 Ais a transverse section on line 3--3 of Figure 1; and

Figures 4 and 5 are fragmentary details of certain portions of themechanism illustrated in Figure 1.

In order to facilitate an understanding of the invention, reference ismade to the embodiment thereof shown in the accompanying drawing anddetailed descriptive language is employed. It will nevertheless beunderstood that no limitation of the inventionis thereby intended andthat various changes and alterations are contemplated such asy wouldordinarily occur to one skilled in the art 'to which the inventionrelates.

Referring to Figure 1, the variable speed drive of the present inventioncomprises generally a driving shaft I0, von which is secured a drivingelement II, and on which is journalled a driven element' I2. Although itis apparent that the driving element II might be made4 integral with theshaft I0, in the present embodiment, the element II is illustratedasfcmprising a sleeve I3, 'lsplined to the shaft I0, and a disc portionI4, integral `with the sleeve I3 and having an annular axially extendingflange I5. The driven element I2 is generally cylindrical, and its outersurface may,- as illustrated, comprise a plain surface to serve as apulley, or may be provided' with gear teeth, sprocket teeth, or thelike, as desired. The driven element I2 is provided with an inwardlyextending annular flange I6 which is journalled on the sleeve I3 bymeans of an anti-friction vbearing I8. Spacedfrom the filange wand'secured in any suitable manner within the driven element I2 is anannular member I1 which serves to support the element I2 on the-sleeveI3 by means of a second antifriction bearing I9. The annular member I'I2 may, if desired, be made integral with the driven element I2, butpreferably takes the form of a separate element, for convenience ofassembly.

The end of the'driven elevent I2 is closed by i a cover plate 20.

The outer surface of the flange I5 of the driving element is providedwith a continuous series `of semi-cylindrical axially extending grooves2l,

as best seen in Figure-2, and the adjacent inner surface'of the drivenelement I2 is provided with a like series of axially extendingsemi-cylindrical grooves 22. The grooved portion of the driven ,elementI2 closely encircles the grooved flange I5 sothat, when at rest, the twomembers define acircular series of cylindrical chambers, connected bynarrowslits, the width of the slits cor-'- responding to the necessarymechanical clear-- ance between the flange vI5 andthe driven elementvI2. For vconvenience in manufacturing, the driving 'element II andldriven e1e'men`tI2 may be assembled together, and a series ofcylindrical recesses drilled along their line of juncture, `to form thecomplementary semi-cylindrical recesses 2| and 22 inthe respectiveAelements, after which the elements are sperated and y`machined -toprovide the necessary. lclearance therebetween'. -v

A cup-shaped pump jacket 23, comprising a cylindrical portion 2 4 and adisc portion 25, is" eccentrically disposed within the flange I5, and`is secured thereto by means of screws or other suitable means. The spacebetween the pump` 29, which is supported on a shaft 33, the latterextending through a central aperture in the disc portion 25 of the pumpjacket. At its opposite end, the shaft is clamped in a split boss 3|carried by a bracket 32, which in turn is secured to any suitable fixedobject or framework` Theshaft 30 is therefore prevented from rotating,l

and while the member 29 is described as a rotor. and serves the functionof the umial vane pump rotor, it will be understood that the rotor 23 isin fact stationary, while the jacket 23 rotates with the driving elementII and shaft `4I l. The rotor 23 is slotted for the reception of springpressed vanes 33 and 34A (Figure 2), which co- I operate with thejacket' 23 in the usual manner to effect the pumping action. I'he pumpchamber 28', i. e., the space between the rotor 23 and jacket 23,communicates with the iiuid chamber 21 through an outlet port 35`extending through the jacket 23, and with a fluid reservoir to be de-iscribed, by means of a conduit 36, formed in the pump jacket 23, whichin turn communicates with a short pipe 31.

The disc portion 25 of the pump jacket is provided with three spacedvalve openings 3 8 (Figure 3). communicating y with the fluid chamber Y21, and adapted to be closed by valve elements. 33

.(Flgure 1) carried on a valve disc 48. 'Ihe latter is rotatably andslidably mounted `on the shaft 30 and is adapted'toube moved toward andaway from the pump .jacket 23 to open and close the valve openings 3 8.through a suitable aperture in the valve disc 4II,

which is adapted to rotatewith the driving ele-- ment II and pump jacket23.

A cup-shaped cover member 4I is' bolted-or `otherwise suitably securedto theilanged, adja- The pipe 31 extends.

alarmenV v cent edge of the drivenl element I2, to provide a fluidreservoir 4I and to enclose the governing mechanism to be described. Thelatter comprisesv a collar 42, loosely mounted on the shaft 30 and-separated from the valve disc 40 by a roller bearing 43. Al pair ofoppositely disposed links 44 are pvotally secured to the collar 42, 'anda similar paiiof links 45 are pivoted to brackets 46 carried on theinner -face of the cupshaped member 4 I. The flyweights 41 are pivotallysecured at the outer ends of the links 44 and 45, to form a centrifugalgovernor of more or less conventional type, the necessary resistance tothe outward movement of the fly- `weights being provided by a spring 48under compression between the collar 42 and a disc 49. The latter isseparated by a ball bearing 50 from a backing pin 5I which extendsthrough a suitable elongated slot in the shaft 30and is adjustablealongsaid slot by means of an -adjusting screw 52 threaded into the'endof the shaft 30 (Figure 5).. It will thusv be seen that the tension ofthe spring v48 may be varied at will by meansvofvthe screw 52, thespring 48 serving to maintain the pin 5I in engagement with the end ofthe screw 52 at all'times.

The operation of the device .is as follows: A

Ysuitablequantity of fluid, preferably oil, is maintained in thereservoir 4I'. When the driven member I2 is at rest and rotation of thedriving Ashaft II) is initiated, vfluid from the reservoir III' will bedrawn into the uid chamber 21 through the pipe 31, conduit 36, pumpchamber 29' and port 35, where the fluid will be under a certainpressure, depending upon the speed at which the shaft I0 isl rotating.The uid under pressure 4in the chamber 21 passes out through the ports28 into the semi-cylindrical grooves 2| of the driving element I,I and,as the latter rotates, will be thrown into the corresponding grooves ofthe driven element I2, causing the By virtue of the shape of thecomplementary grooves of the two elements, and Athe small clearancebetween them, it has been latter to rotate.

found that a relatively large torque maybe -transmitted by the presentdevice, as compared to previously known hydraulic drives. It has alsovbeen found .that the torque transmitted, andv hence the speed of thedriven element relative to the driving element, depends upon thepressure of the fluid inthe chamber 21 and hence in the space betweenthe driving and driven elements.

As the driven element I2 approaches-the desired speed, the centrifugalgovernor operates to relieve the pressure of the spring 48 upon thevalve disc 40, which latter will accordingly move outwardly, partlyopening the valve openings 38,

iand relieve the pressure in the chamber 21. In this manner.. the speedof the driven element I2 is prevented from going above the desiredspeed, and is effectively regulated at that speed. In order 'tochangethe speed of the driven element, it is onlynecessary to adjust thetension of the vspring 48 by means of the adjusting screw 52.

j I-do lnot desire to be bound by any theory as tothe operation of mynovel drive, but it is-a fact that the torque transmitted varies with.the pressure of the fluid* in the chamber 21. One possible explanation,when using oil as the transmission medium, isthat since the oilundoubtedly contains a certain amount of entrained air, the higher thevpressure in the space between the driving and driven elements, the moreoil is present.` Of course, when using a compressi-ble meamm, it isobvious met the higher the pressure the greater will be the mass of themedium compressed between the driving and driven elements. l

claimed as new and desired to be secured by Letv ters Patent is: i

l. A variable speed drive comprising a driving shaft, an externallytoothed annular member secured on said shaft, a rotatably mounted drivenmember closely encircling saidl annular member, said driven memberhaving internal teeth corre-I sponding to the external teeth of saidannular member, means for supplying a uid under pressure to theperiphery of said annular member, and means controlled in accordancewith the rotational speed of said driven member for varying the pressureof the fluid supplied to theperiphery of said annular member.

2. A variable speed drive according to claim l, said fluid supply meanscomprising a pump disposed wlthin said annular'member and actuated bysaid driving shaft.

3. A variable speed drive comprising a driving shaft, an annular membersecured thereon and having on its periphery a continuous series ofaxially extending grooves, a rotatably mounted driven member closelyencircling said annular member and having on its inner surface acontinuous series of axially extending grooves, means for supplying afluid under pressure to the space between said annular and drivenmembers, and means controlled according to the rotational i speed ofsaid driven member for varying the pressure of the fluid supplied tosaidspace.

4. A variable speed drive comprising a driving shaft, an annular membersecured thereon and having on its periphery a continuous series ofsemi-cylindrical axially extending grooves, a driven mem-ber closelyencircling said annular member and having on itsinner surface acorresponding series of semi-cylindrical grooves, means for supplying afluid under pressure to the space between said annular and drivenmembers, and means restricting the flow of fluid out of said space.

5. A variable speed drive according to claim 4, said fluid supply meanscomprising a pump disposed within said annular member and actuated bysaid driving shaft.

6. A variable speed said pressure varying means comprising a centrifugaldevice including a spring, and manually operated means for varying thetension of saidl spring.

7. A variable speedv drive comprising a driving shaft, a member securedon said shaft having an axially extending peripheral flange, said flangehaving on its outer surface a continuous series of axially extendinggrooves, a drivenl member journalled on said shaft and closelyencircling said flange, said driven member having on its inner surface acorresponding series of grooves, a cylindrical pumpjacket eccentricallyg disposed within said flange and forming therewith a fluid chamber,ports connecting said fluid chamber with each said groove in saidflange, a fluid reservoir, pump means within said jacket,

drive according to claim 1,l

a conduit connecting said fluid reservoir and said pump means, an outletport connecting said pump means with said fluid chamber, means forregulating the fluid pressure in said chamber, and means controlled bythe rotational'speed of .said driven member for actuatingsaid pressurecontrol means.

8. A variable speed drive comprising a driving shaft, a member securedon'said shaft having an axially'extendlng peripheral flange, said flange.having on its outer surface a continuous surface of axially extendinggrooves, a driven member journalled on said shaft and closelyen-"circling said flange, said driven member having on its inner surface acorresponding series lof grooves, a cylindrical pump jacketeccentrically disposedwithin said flange and forming therewith a fluidchamber, ports connecting said fluid chamber with each said groove insaid flange, a fluid reservoir, pump means within said jacket, a conduitconnecting said uid reservoir and said pump means, an outlet portconnecting said pump means with said fluid chamber, means for regulatingthe fluid pressure in said chamber, and means controlled by therotational speed of said driven member for actuating said pressurecontrol means, said last means comprising 'a centrifugal deviceincluding a spring, and manually operated means for varying the tensionof said spring.

9. A variable speed drive comprising a driving shaft, .a member securedon said shaft having an axially extending peripheral flange, said flangehaving on its outer surface a continuous surface of axially extendinggrooves, a driven member journalled on said shaft and closely encirclingsaid flange, said drivenmember having on its inner surface acorresponding series of grooves,

a cylindrical pump jacket eccentrically diseach said groove in saidflange, a fluid reservoir, l

pump means within said jacket, a conduit connecting said fluid reservoirand said pump means, an outlet port extending through said jacket andconnecting said pump means with said lfluid chamber, valve means forregulating thefiuid pressure in said chamber, and means controlled bythe rotational speed of said driven member for actuating said valvemeans, said last meanscomprising a centrifugal device including aspring, and manually operated means for varying the tension of saidspring. f

10. A variable speed drive comprising a driving shaft, a member securedon said shaft and comprising a disc portion having an axiallyy extendingperipheral ilange, said flange having on its outer surface a continuoussurface of semicylindrical axially extending grooves, a driven" memberjournalled on Isaid shaft and closely enr circling said flange, saiddriven member having onv its inner surface a corresponding series ofsemi-cylindrical grooves, a cylindrical pump jacket eccentricallydisposed within said flange and forming therewith a fluid chamber, portsextending through said flange and connecting said fluid chamber witheach said groove in said flange, a fluid reservoir, pump means withinsaid jacket, a conduit connecting said fluid reservoir and said pumpmeans, an outlet port extending through said jacket andconnecting saidpump driven member for actuating said valve means, said last meanscomprising a centrifugal device including a spring, and manuallyoperated means for varying the tension of said spring.

1i. A variable speed drive comprising a rotatable driving member havinga generally cylim drical, transversely grooved, external surface, arotatable driven member affording a generally cylindrical, transverselygrooved, internal surtace surrounding and disposed in close proximity tosaid first named surface. means for supplying iiuid under pressurebetween said surfaces, and means for altering the pressure of the -fluidthus supplied to vary the speed ratio between said members.

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